Heat the butter in a skillet on medium-high heat. Add the vegetables and stir fry 5 minutes or until vegetables are tender-crisp.
Add the finely chopped tomatoes, tomato paste, vegetable stock cube, basil, chili powder salt and pepper. Let simmer for 8 to 10 minutes.
Preheat the oven to 200 degrees.
Make the cheese topping by mixing shredded cheese, creme fraiche and parmesan cheese, salt and pepper.
Place lasagna sheets and pasta sauce in layers in a baking dish.
Spread the cheese topping mixture on top and finish with another layer of shredded cheese.
Bake in the oven for about 40 minutes or until the lasagna has a nicely browned surface.